SEC Petition Evaluation Report 

Petition SEC-00067 

Report Rev # 0 Report Submittal Date __11/10/06________ 

Subject Expert(s): Cindy Bloom 

Site Expert(s): 

Petitioner Administrative Summary 

Petition Under Evaluation 

Petition # Petition 

Type 

Petition A 

Receipt Date DOE/AWE Facility Name 

SEC-00067 83.14 September 6, 2006 Allied Chemical Corporation Plant 

Proposed Class Definition 

All AWE employees who were monitored, or should have been monitored, for exposure to ionizing 

radiation while working at the Allied Chemical Corporation Plant in Metropolis, Illinois, for a number 

of work days aggregating at least 250 work days from January 1, 1959 through December 31, 1976 or 

in combination with work days within the parameters established for one or more other classes of 

employees in the SEC.

Related Petition Summary Information 

SEC Petition Tracking #(s) Petition Type DOE/AWE Facility Name Petition Status 

NONE

Related Evaluation Report Information 

Report Title DOE/AWE Facility Name 

NONE

ORAU Lead Technical Evaluator: 

Monica Harrison-Maples

ORAU Review Completed By:

Michael S. Kubiak 

Peer Review Completed By: [Signature on file] 11/16/06 

LaVon Rutherford Date 

SEC Petition Evaluation Reviewed By: [Signature on file] 11/27/06 

Jim Neton Date 

SEC Evaluation Approved By: [Signature on file] 12/01/06 

Larry Elliott Date 
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Evaluation Report Summary: SEC-00067, Allied Chemical Corporation Plant 

This evaluation report by the National Institute for Occupational Safety and Health (NIOSH) 

addresses a class of employees proposed for addition to the Special Exposure Cohort (SEC) per the 

Energy Employees Occupational Illness Compensation Program Act of 2000, as amended, 42 U.S.C. 

§ 7384 et seq. (EEOICPA) and 42 C.F.R. pt. 83, Procedures for Designating Classes of Employees as 

Members of the Special Exposure Cohort Under the Energy Employees Occupational Illness 

Compensation Program Act of 2000. 

NIOSH-Proposed Class Definition

The NIOSH-proposed class includes all Atomic Weapons Employer (AWE) employees who were 

monitored, or should have been monitored, for exposure to ionizing radiation while working at the 

Allied Chemical Corporation Plant in Metropolis, Illinois, for a number of work days aggregating at 

least 250 work days from January 1, 1959 through December 31, 1976 or in combination with work 

days within the parameters established for one or more other classes of employees in the SEC.

Feasibility of Dose Reconstruction

Per EEOICPA and 42 C.F.R. § 83.14(b), NIOSH has established that it does not have sufficient 

information to complete dose reconstructions for individual members of the class with sufficient 

accuracy. NIOSH does not have access to sufficient personal monitoring data or workplace 

monitoring data to adequately determine the potential intake of non-uranium radionuclides; therefore, 

NIOSH does not have sufficient information to estimate with sufficient accuracy the internal radiation 

doses of the class of employees covered by this SEC evaluation. 

With the data currently available to NIOSH, it appears to be feasible to reconstruct with sufficient 

accuracy external doses, as well as internal doses from uranium, for those Allied Chemical 

Corporation Plant workers who were monitored for uranium for the covered period from January 1, 

1959 through December 31, 1976. 

Health Endangerment Determination

The NIOSH evaluation did not identify evidence from the petitioners or from other sources that would 

establish the class was exposed to radiation during a discrete incident likely to have involved 

exceptionally high-level exposures. However, the evidence reviewed in this evaluation indicates that 

some workers in the class may have accumulated chronic radiation exposures through unmonitored 

intakes of non-uranium radionuclides. Therefore, the regulation [42 C.F.R. § 83.13(c)(3)(ii)] requires 

NIOSH to specify that health may have been endangered for those workers covered by this evaluation 

who were employed for a number of work days aggregating at least 250 work days within the 

parameters established for this class or in combination with work days within the parameters 

established for one or more other classes of employees in the SEC. 
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Table of Contents 

Evaluation Report Summary: SEC-00067, Allied Chemical Corporation Plant..................................... 3 

1.0 Purpose and Scope....................................................................................................................... 7 

2.0 Introduction ................................................................................................................................. 7 

3.0 NIOSH-Proposed Class Definition and Petition Basis................................................................ 8 

4.0 Radiological Operations Relevant to the Proposed Class ........................................................... 8 

4.1 Allied Chemical Corporation Plant Description................................................................ 8 

4.2 Allied Functional Areas...................................................................................................... 9 

4.3 Radiological Exposures.................................................................................................... 11 

4.3.1 External Exposures............................................................................................... 11 

4.3.2 Internal Exposures................................................................................................ 11 

5.0 Summary of Available Monitoring Data for the Proposed Class.............................................. 12 

5.1 Allied Internal Monitoring Data....................................................................................... 13 

5.2 Allied External Monitoring Data...................................................................................... 13 

5.3 Allied Workplace Monitoring Data.................................................................................. 14 

6.0 Feasibility of Dose Reconstruction for the Proposed Class ...................................................... 14 

6.1 Feasibility of Estimating Internal Exposures ................................................................... 15 

6.2 Feasibility of Estimating External Exposures .................................................................. 16 

7.0 Summary of Feasibility Findings for Petition SEC-00067........................................................ 17 

8.0 Evaluation of Health Endangerment for Petition SEC-00067................................................... 17 

9.0 NIOSH-Proposed Class for Petition SEC-00067 ...................................................................... 18 

10.0 References ................................................................................................................................. 19 

Figure 

4-1: Ore to Uranium Hexafluoride Conversion Process........................................................................ 10 
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SEC Petition Evaluation Report for SEC-00067 

1.0 Purpose and Scope 

This report evaluates the feasibility of reconstructing doses for employees who worked at the Allied 

Chemical Corporation Plant (Allied) in Metropolis, Illinois, from January 1, 1959 through December 

31, 1976. It provides information and analysis germane to considering a petition for adding a class of 

employees to the Congressionally-created SEC. 

This report does not provide any determinations concerning the feasibility of dose reconstruction that 

necessarily apply to any individual energy employee who might require a dose reconstruction from 

NIOSH, with the exception of the employee whose dose reconstruction could not be completed, and 

whose claim consequently led to this petition evaluation. The finding in this report is not the final 

determination as to whether or not the proposed class will be added to the SEC (see Section 2.0). This 

report will be considered by the Advisory Board on Radiation and Worker Health (the Board) and by 

the Secretary of Health and Human Services (HHS). The Secretary of HHS will make final decisions 

concerning whether or not to add one or more classes to the SEC in response to the petition addressed 

by this report. 

This evaluation, in which NIOSH provides its findings on both the feasibility of estimating radiation 

doses of members of this class with sufficient accuracy and on health endangerment, was conducted in 

accordance with the requirements of EEOICPA and 42 C.F.R. § 83.14. 

2.0 Introduction 

Both EEOICPA and 42 C.F.R. pt. 83 require NIOSH to evaluate qualified petitions requesting the 

Department of Health and Human Services to add a class of employees to the SEC. The evaluation is 

intended to provide a fair, science-based determination of whether it is feasible to estimate, with 

sufficient accuracy, the radiation doses of the proposed class of employees through NIOSH dose 

reconstructions.1

NIOSH is required to document its evaluation in a report, and to do so, relies on its own dose 

reconstruction expertise as well as technical support from its contractor, Oak Ridge Associated 

Universities (ORAU). Once completed, NIOSH provides the report to both the petitioners and to the 

Advisory Board on Radiation and Worker Health (Board). The Board will consider the NIOSH 

evaluation report, together with the petition, comments of the petitioner(s) and such other information 

as the Board considers appropriate, to make recommendations to the Secretary of HHS on whether or 

not to add one or more classes of employees to the SEC. Once NIOSH has received and considered 

the advice of the Board, the Director of NIOSH will propose a decision on behalf of HHS. The 

Secretary of HHS will make the final decision, taking into account the NIOSH evaluation, the advice 

1

 NIOSH dose reconstructions under EEOICPA are performed using the methods promulgated under 42 C.F.R. pt. 82 and 

the detailed implementation guidelines available at www.cdc.gov/niosh/ocas. 
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of the Board, and the proposed decision issued by NIOSH. As part of this final decision process, the 

petitioner(s) may seek a review of certain types of final decisions issued by the Secretary of HHS.2

3.0 NIOSH-Proposed Class Definition and Petition Basis 

This NIOSH report summarizes the methods and findings of the NIOSH SEC evaluation for all AWE 

employees who worked at Allied for the period from January 1, 1959 through December 31, 1976 for 

a number of days aggregating at least 250 work days, occurring either solely under this employment 

or in combination with work days of employment occurring within the parameters established for 

other classes of employees included in the SEC. During this period, employees at this facility were 

involved in converting uranium ore concentrates to UF6 feed material for the gaseous diffusion 

enrichment process. 

The evaluation responds to Petition SEC-00067, which was submitted by an EEOICPA claimant who 

was employed at the facility during this period as an ore preparation assistant and operator, a 

fluorination assistant and operator, a green salt (UF6) operator, a distillation operator, a yard operator, 

and an F2 products cylinder handler. This EEOICPA claimant’s dose reconstruction could not be 

completed by NIOSH because of a lack of sufficient dosimetry-related information about non-uranium 

radionuclide components of the feed material and/or waste streams as a potential source of internal 

radiological exposure (i.e., lead-210, polonium-210, radium-226, actinium-227, thorium-228, 

thorium-230, thorium-232, and protactinium-231).3 The NIOSH determination that it is unable to 

complete a dose reconstruction for a EEOICPA claimant is a qualified basis for submitting an SEC 

petition pursuant to 42 C.F.R. § 83.9(b). 

4.0 Radiological Operations Relevant to the Proposed Class 

The following subsections summarize the radiological operations at Allied Chemical from January 

1959 to December 1976, and the information available to NIOSH to characterize particular processes 

and radioactive source materials. From available sources NIOSH has gathered process and source 

descriptions, information regarding the identity and quantities of radionuclides of concern, and 

information describing the processes through which the radiation exposures of concern may have 

occurred and the physical environment in which they may have occurred. The information included 

within this evaluation report is meant only to be a summary of the available information. 

4.1 Allied Chemical Corporation Plant Description 

After World War II, uranium in the form of concentrates and high-grade ores was refined by 

companies like Allied Chemical to produce feed material for gaseous diffusion uranium enrichment 

for the U.S. government. The K-25 gaseous diffusion plant in Oak Ridge, Tennessee, was expanded 

between 1946 and 1954, and gaseous diffusion plants were built at Paducah, KY and Piketon, OH in 

2

 See 42 C.F.R. pt. 83 for a full description of the procedures summarized here. Additional internal procedures are 

available at www.cdc.gov/niosh/ocas. 3

 The term “non-uranium radionuclides” will be used throughout this document to collectively designate lead-210, 

polonium-210, radium-226, actinium-227, thorium-228, thorium-230, thorium-232, and protactinium-231. 
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the early and mid-1950s. The Allied Chemical Corporation Plant near Metropolis, Illinois, converted 

uranium ore concentrates to UF6 for feed for the Paducah Gaseous Diffusion Plant. The concentrates 

contained approximately 70-75% uranium and various impurities, depending on the mill circuit and 

the original concentrations of ore impurities (Perkins, 1982). These concentrates were converted, 

using the fluoride volatility process, into gaseous UF6. This product was then sent to an enrichment 

facility to increase the concentration of the desirable uranium-235 isotope. 

The Allied plant, located at 101 Columbia Road in Massac County, Illinois, was originally contracted 

in 1959 to process 5,000 tons of U3O8 per year. By 1982, the plant’s throughput capacity had been 

increased to 14,000 tons of uranium per year and the facility had processed over 100,000 tons of 

uranium. The UF6 production facility used a “dry” conversion process (versus a “wet” chemical 

solvent extraction process [Perkins, 1982]). The plant operated under an Atomic Energy Commission 

(AEC) contract through June 30, 1964 when it was temporarily closed; it resumed operations in 

February 1968. The facility is now owned by Honeywell, and still provides UF6 to gaseous diffusion 

plants for use in the commercial sector. The facility currently operates under a Nuclear Regulatory 

Commission (NRC) license. 

Allied was an Atomic Weapons Employer for the period 1959 through 1976, and was also known both 

as General Chemical Division and as Allied Signal Metropolis Plant. 

4.2 Allied Functional Areas 

Allied Chemical operations included the following functional areas: 

• Receiving and Sampling: Ore concentrates were received and sampled for uranium assay and 

moisture content. 

• Pre-treatment: Incoming uranium concentrates containing sodium, and the uranium concentrates 

produced by the uranium recovery activities, were pre-treated to remove sodium and potassium 

impurities. Pre-treatment was necessary because sodium formed a compound that caused caking 

and sintering in the fluorination fluid beds. 

• Ore Preparation: As a first step, incoming ore and recovered uranium were dried. The materials 

were then blended, agglomerated, crushed, and sized before being sent to the reduction circuit. 

• Reduction: The U3O8 was fed into the reductor vessel where it was mixed with N2, H2 and 

additional nitrogen to form a fluidized bed and then reduced to UO2.

• Hydrofluorination: The UO2 from the reduction process was reacted with HF to form UF4.

• Fluorination: The UF4 from the hydrofluorination process was fed into fluid bed reactors where, 

by introducing fluorine (F2), the UF4 was converted into gaseous UF6. The gaseous UF6 from the 

column was condensed in two cold traps operated in series. The UF6 was transferred to UF6 

shipping cylinders by melting the UF6 and allowing the material to drain into the cylinders. 

(Perkins, 1982) 
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• Uranium Recovery and Reprocessing: Uranium was recovered from waste material through 

calcining (drying) the various uranium-containing sludges derived throughout the process, 

grinding the material into a fine powder, leaching the material using a sodium carbonate solution 

to solubilize the uranium, and precipitating the uranium from the solution using NaOH. 

• Cylinder Wash: Uranium was recovered from cylinders containing residual UF6 and uranium 

daughters that were returned to Allied from the enrichment facilities. 

Figure 4-1 (reprinted from the Allied Site Profile) describes the process of conversion from ore 

concentrates to uranium hexafluoride (ORAUT-TKBS-0044): 

Figure 4-1: Ore to Uranium Hexafluoride Conversion Process 
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4.3 Radiological Exposures 

Potential radiological exposures at Allied resulted from uranium ore, ore concentrates, and 

non-uranium radionuclide contaminants in the milled uranium ore. The forms of uranium may have 

included all solubility types: Type F (fast dissolution and high level of absorption to blood); Type M 

(intermediate rate of dissolution and level of absorption to blood); and Type S (slow dissolution rate 

and low level of absorption to blood). Additional radiological exposure resulted from the 

non-uranium contaminants assumed to have arrived with the ore concentrate. The source term activity 

ratios of the contaminants relative to uranium are not sufficiently understood to allow a plausible 

bounding estimate of the radiological exposure the contaminants contributed. The exposure scenario 

is further complicated by the concentration of non-uranium radionuclides (in unknown ratios) by the 

processes. Such concentration would have been maximal in the fluorination bed ash and other waste 

streams. 

The feed preparation, reduction, hydrofluorination, and fluorination circuits were all located in the 

Feed Materials Building. Other locations having significant potential for radiological exposures were 

the ore sampling building, the ore storage pads, all waste handling or storage facilities, and the 

laboratory building. 

4.3.1 External Exposures 

External exposures to Allied personnel were monitored using film badges until April 1976, with 

results for photon and beta exposures reported. Potential photon exposures were primarily in the 30 to 

250 keV energy range; potential electron exposures were above 15 keV. There was some potential for 

neutron exposure from alpha particle collision reactions, with neutron energies in the 0.1 to 2 MeV 

range. 

Processing uranium concentrates results in a concentration of non-uranium radionuclides in the 

by-products, with the associated beta and gamma radiation fields contributing to potential external 

dose. 

The fluorination bed ash was known to contain short-lived uranium progeny radionuclides. Because 

these impurities accumulate, the ash had to be withdrawn, drummed, and stored long enough to allow 

the uranium daughters thorium-234 and protactinium-234m to decay. This work potentially resulted 

in elevated beta and gamma radiation fields contributing to higher extremity doses for individuals 

handling the fluorination ash or decontaminating equipment used to contain or transport the bed ash 

(ORAUT-TKBS-0044). 

4.3.2 Internal Exposures 

The primary internal radiation exposure hazard at the Allied plant was radiological dust produced 

from processing uranium concentrates (ORAUT-TKBS-0044). During the operational period 

considered by this evaluation, the drums of uranium concentrates received for processing were 

weighed and sampled using a falling stream method. The ore preparation cycle physically blended, 

agglomerated, crushed, and sized the feed material. Both of these cycles potentially generated 

airborne dust that could have been inhaled or ingested. 
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The Allied facilities used engineering controls and ventilation equipment as the primary method to 

reduce employee or environmental radiation/radioactivity exposure. When unconfined material was 

to be handled, ventilation controls were relied on to reduce exposure. Building exhaust points were 

monitored to determine workroom air activity and environmental uranium loss. 

Allied considered the following job categories to involve work in areas with significant internal 

exposure potential from un-encapsulated uranium processing (Bioassay, 1986): 

• Ore preparation operators and assistants 

• UF4 operators and assistants 

• Fluorination operators and assistants 

• Distillation operators and assistants 

• Decontamination employees 

• Shift breakers and relief operators working in the Feed Materials process area 

• Sampling plant employees 

• Mechanics in the Feed Materials buildings and Sampling Plant 

• Production and maintenance foremen and shift supervisors in the Feed Materials building 

• Health physics technicians assigned to the Feed Materials building or Sampling Plant 

• Electricians 

• Instrument personnel 

• Laboratory technicians 

NIOSH has compiled and published a more complete summary of the information available to it 

regarding the exposures at Allied. This information is summarized in the Allied Site Profile 

document, ORAUT-TKBS-0044, and is available online from http://www.cdc.gov/niosh/ocas. 

5.0 Summary of Available Monitoring Data for the Proposed Class 

The primary data used for determining internal exposures are derived from personal monitoring data, 

such as urinalyses, fecal samples, and whole body counting results. If these are unavailable, the air 

monitoring data from breathing zone and general area monitoring are used to estimate the potential 

internal exposure. If personal monitoring and breathing zone area monitoring are unavailable, internal 

exposures can sometimes be estimated using more general area monitoring, process information, and 

information characterizing and quantifying the source term. 

This same hierarchy is used for determining external exposures to the cancer site. Personal 

monitoring data from film badges or thermoluminescent dosimeters (TLDs) comprise the primary data 

used to determine such external exposures. If there are no personal monitoring data, exposure rate 

surveys, process knowledge, and source term modeling can sometimes be used to reconstruct the 

potential exposure. 

A more detailed discussion of the information required for dose reconstruction can be found in 

OCAS-IG-001, Internal Dose Reconstruction Implementation Guide and OCAS-IG-002, External 

Dose Reconstruction Implementation Guide. These documents are available at: 

http://www.cdc.gov/niosh/ocas/ocasdose.html. 
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5.1 Allied Internal Monitoring Data 

Individual uranium urinalysis data are available from as early as December 1958. Urinalysis was 

done in-house and was routine at Allied. Indications are that most employees, including 

administrative staff and contract workers, participated in the in vitro bioassay program. 

Allied’s 1982 NRC License Renewal Application describes whole-body-counting bioassay performed 

to determine the lung deposition of insoluble natural uranium (Site Procedures, 1985). The earliest in 

vivo data available to NIOSH are dated December 1978, after the Allied Chemical covered period. 

Because any soluble material will clear from the lung compartment, these post-AEC in vivo data are 

only useful qualitatively to assure that calculated intakes based on earlier urinalysis results do not 

over-predict observed lung activity. 

NIOSH has reviewed the available claimant data, and for the 74 Allied Chemical claim files with 

monitoring data, NIOSH currently has 17,949 urinalysis results and 623 in vivo results, none of which 

are non-uranium radionuclide sampling results. An Allied Chemical site policy and procedure 

document supports NIOSH’s finding that non-uranium analysis was not performed (Bioassay, 1986). 

The policy document only addresses possible employee exposures to the uranium component of the 

uranium ore concentrates, UF4, UO2, UF6, or UO2F2. Determination of internal exposures specific to 

non-uranium radionuclides, including thorium-230, thorium-232, thorium-238, radium-226, lead-210, 

protactinium-231, and actinium-227 did not occur within the AWE operational period (ending 

December 31, 1976). 

5.2 Allied External Monitoring Data 

The earliest available Allied external dosimetry results are dated January 1, 1959 (ORAUT-TKBS0044). External whole body dosimetry results are available for all 74 claims examined by NIOSH, 

and there are indications that external monitoring data are likely available for Allied workers for the 

entire AWE operational period (January 1959 through December 1976). 

Beginning in 1969, external dosimetry services using film badges were provided by R. S. Landauer, 

Jr. and Company. Prior to the Landauer records, external monitoring data are handwritten and do not 

include information identifying the company providing the service or the method of measurement. In 

mid-1976, Eberline Instrument Company began to provide TLD services to Allied Chemical 

(ORAUT-TKBS-0044). Landauer documentation indicates that the Landauer dosimetry reported 

exposures in millirem ranging from 30 KeV to 20 MeV for photons, 1.5 MeV and above for betas, and 

1-10 MeV for neutrons. Any photon exposures below 10 millirem, hard beta exposures below 40 

millirem, fast neutron exposures below 20 millirem, or thermal neutron exposures below 10 millirem 

were recorded as “M” for minimum quantity measurable. (Landauer, 1970) 

Personnel working in areas where potential neutron exposure could occur were issued film badges 

sensitive to beta, gamma, and neutron radiation. Otherwise, personnel were issued film badges 

sensitive to only beta and gamma radiation. Available Allied records show that the typical badge 

exchange frequency was monthly. 
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NIOSH has found no documented Allied Chemical requirement for occupationally-required medical 

X-ray examinations. More than half of the claimant interviews documented by NIOSH indicate that 

chest X-ray examinations were routine and a significant number of such interviews indicate the 

frequency was annual. 

5.3 Allied Workplace Monitoring Data 

Summaries of results are available for daily stationary breathing zone samples collected in various 

uranium work areas since 1985 (ORAUT-TKBS-0044). Also as of 1985, surface-removable 

contamination measurements were performed routinely in selected areas, but were only counted for 

alpha radioactivity. These surveys appear to have been used primarily to direct clean-up efforts; only 

limited summaries of these data are available at this time. NIOSH has no documentation that suggests 

non-uranium materials were specifically identified, or monitored for, by air sampling. The limited air 

sampling data available for review during the development of the Site Profile indicate that 

concentrations were trending downward over time. The airborne concentrations were reported in units 

of micro-curies of uranium per milliliter (uCi/ml), but it appears there was no chemical processing of 

the sample filters. Indications are that the results were actually based on gross alpha counting, and 

therefore, would include long-lived non-uranium alpha emitters; however, NIOSH has located no 

documentation that would allow sufficiently accurate estimation of non-uranium activity levels 

(ORAUT-TKBS-0044). 

Reference materials dated after the covered period indicate that surface contamination measurements 

were routinely performed in uranium and non-uranium areas and used as a basis for decontamination; 

however, NIOSH has been unable to locate applicable area survey data (ORAUT-TKBS-0044). 

6.0 Feasibility of Dose Reconstruction for the Proposed Class 

42 C.F.R. § 83.14(b) states that HHS will consider a NIOSH determination that there was insufficient 

information to complete a dose reconstruction, as indicated in this present case, to be sufficient,

without further consideration, to conclude that it is not feasible to estimate the levels of radiation 

doses of individual members of the class with sufficient accuracy. 

In the case of a petition submitted to NIOSH under 42 C.F.R. § 83.9(b), NIOSH has already 

completed research to determine that a dose reconstruction cannot be completed for an employee at 

the DOE or AWE facility. This determination by NIOSH provides the basis for the petition by the 

affected claimant. NIOSH has further considered defining the extent of the class of employees who 

are similarly affected, as indicated by the completed research, and hence, as a class of employees, 

dose reconstruction is similarly not feasible. 

In accordance with 42 C.F.R. § 83.14(a), NIOSH also considered whether or not the completed 

research provides a basis for evaluating an additional class at the facility for whom NIOSH may 

believe that dose reconstruction is unlikely to be feasible. If NIOSH were to identify such a basis, it 

would undertake a separate SEC evaluation regarding the additional class. This would allow NIOSH, 

the Board, and HHS to complete, without delay, their consideration of the class including a claimant 

for whom NIOSH has already determined a dose reconstruction cannot be completed, and whose only 

possible remedy under EEOICPA would be through adding a class of employees to the SEC. 
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This section of the report summarizes research findings by which NIOSH determined that it lacked 

sufficient information to complete the relevant dose reconstruction and on which basis it has defined 

the class of employees for which dose reconstruction is not feasible. NIOSH’s determination relies on 

the same statutory and regulatory criteria that govern consideration of all SEC petitions. 

6.1 Feasibility of Estimating Internal Exposures 

Participation in uranium bioassay monitoring programs by Allied employees was widespread from the 

start of AEC operations and there appears to be sufficient information to assess their uranium intakes 

and resulting internal dose from uranium. However, as discussed in Section 4.3, the potential for the 

presence of thorium, radium, and other non-uranium radionuclides existed at Allied in all radiological 

areas. A review of the available documentation indicates that analysis of in vitro bioassay samples for 

non-uranium radionuclides was not performed at Allied, and that non-uranium in vitro bioassay data 

are unavailable. As discussed in Section 5.1, the available in vivo data were all collected after the 

Allied covered period and cannot be used to bound the total intakes that may have occurred during the 

AWE operational period. Due to the lack of non-uranium bioassay data, NIOSH concludes that the 

available bioassay data do not provide the information necessary to adequately assess non-uranium 

intakes at the Allied facility. 

Health physics reports for later years indicate a continuous reduction in air concentrations over time. 

This apparent reduction in workplace airborne contamination levels is supported by an overall 

downward trend in bioassay results. These downward trends indicate that the available airborne 

monitoring results for periods after the Allied covered period are not representative of the airborne 

levels that would have existed during AEC work, when air monitoring results are unavailable. The 

currently-available air monitoring data, therefore, are insufficient for bounding the air concentrations 

during the Allied AEC operational period. NIOSH has not located sufficient Allied operational area 

air sampling data to support sufficiently accurate dose reconstruction for the covered period. 

Specific source term information regarding the chemical forms and/or solubility of the non-uranium 

radionuclide components of the ore concentrates or of the by-product sludges is not available. The 

absorption type of these radionuclides is not necessarily related to the absorption type of the 

associated uranium; therefore, NIOSH has no basis for determining the actual absorption type for the 

non-uranium radionuclides. In the absence of specific information, attempts were made by NIOSH to 

apply conservative assumptions regarding absorption type and activity levels of non-uranium 

radionuclides. Uranium intakes were estimated using available uranium bioassay results. The intake 

rates for non-uranium radionuclides were then estimated by assuming conservative ratios relative to 

uranium (ORAUT-TKBS-0044). These conservative exposure models resulted in unreasonably high 

estimates of non-uranium radiation dose. Attempts by NIOSH to refine the models also failed to 

result in reasonable estimates of radiation dose, as required by 42 C.F.R. pt. 82. 

Some limited documentation is currently available to match radiological workers to specific locations; 

however, many of these workers were likely assigned to multiple locations. This is confirmed by a 

1996 statement in an Allied Chemical/Honeywell current procedures document (Honeywell, 1996): 
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“...Due to the mobility of the workforce, and the large variety of ore concentrate 

blends processed, it would be an extremely difficult task to track individual 

exposure for each uranium compound to which employees might be exposed.” 

Using job titles or job descriptions to determine which employees might have been exposed to 

radioactive materials would not be accurate for internal dose reconstruction given the available data 

and the documented worker mobility; thus, the proposed class cannot be defined by job title or 

description. 

Non-uranium radiological materials were potentially handled or stored in the Feed Materials building, 

the Sampling Plant, the Sodium Removal and Uranium Recovery facilities, the KOH Muds Washing 

facility, the Calcining facility, the Pond Mud Calciner Drier, the Laboratory building, the Cylinder 

Wash building, the storage facilities, and the outdoor drum storage pads. However, documentation of 

the site activities, especially the storage and transport of radiological materials across the site, is 

insufficient to limit the exposure scenario to these listed locations. Consequently, the proposed class 

cannot be defined by work location. 

With the data currently available to NIOSH, it is not possible to reconstruct with sufficient accuracy 

the non-uranium dose, and therefore the total internal dose, that would have resulted during the Allied 

Chemical Corporation Plant AWE covered period, 1959 through 1976. It appears to be feasible, 

however, to reconstruct with sufficient accuracy internal doses from uranium for those workers who 

were monitored for uranium. 

6.2 Feasibility of Estimating External Exposures 

This evaluation responds to a petition based on NIOSH determining that internal radiation exposures 

to non-uranium radionuclides could not be reconstructed for a dose reconstruction referred to NIOSH 

by the Department of Labor. As noted above, HHS will consider this determination to be sufficient 

without further consideration to determine that it is not feasible to estimate the levels of radiation 

doses of individual members of the class with sufficient accuracy. Consequently, it is not necessary 

for NIOSH to evaluate the feasibility of reconstructing external radiation exposures in this case. 

However, based on the research conducted for this evaluation, NIOSH concludes that it is likely able 

to estimate external exposure to electrons and photons for employees in this class. In addition, it is 

likely that NIOSH could estimate neutron doses using the document, Estimation of Neutron Dose 

Rates from Alpha-Neutron Reactions in Uranium and Thorium Compounds (ORAUT-OTIB-0024). 

Available records indicate that Allied workers were monitored for external whole-body exposures. 

NIOSH considers adequate reconstruction of external dose possible by using individual dosimetry 

records, claimant-favorable assumptions, and the relevant protocols specified in various complex-wide 

Technical Information Bulletins (TIBs). 

In addition, NIOSH considers adequate reconstruction of medical dose for Allied workers feasible by 

applying pertinent claimant-favorable assumptions and protocols specified in the complex-wide 

technical information bulletin ORAUT-OTIB-0006, Technical Information Bulletin: Dose 

Reconstruction from Occupationally Related Diagnostic X-Ray Procedures. 
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7.0 Summary of Feasibility Findings for Petition SEC-00067 

This report evaluates the feasibility for estimating the dose, with sufficient accuracy, for all AWE 

employees at Allied Chemical Corporation Plant from January 1, 1959 through December 31, 1976. 

NIOSH determined that it lacks sufficient bioassay, source term, and workplace monitoring data for 

non-uranium radionuclides to reconstruct the total potential internal exposures at the facility during 

this time period. Consequently, NIOSH finds that it is not feasible to estimate with sufficient 

accuracy the radiation doses resulting from non-uranium internal exposures received by members of 

this class of employees. 

With the data currently available to NIOSH, as presented in the Site Profile (ORAUT-TKBS-0044), it 

appears feasible to reconstruct with sufficient accuracy the external doses, and the internal doses from 

uranium for those workers who were monitored for uranium, that would have resulted during the 

Allied Chemical Corporation Plant AWE operational period (January 1, 1959 through December 31, 

1976). 

NIOSH has documented herein that it cannot complete the dose reconstructions related to this petition. 

The basis of this finding is specified in this report, which demonstrates that NIOSH does not have 

access to sufficient information to estimate with sufficient accuracy either the maximum radiation 

dose incurred by any member of the class or to estimate such radiation doses more precisely than a 

maximum dose estimate. Members of this class at Allied Chemical Corporation Plant may have 

received unmonitored internal radiological exposures from non-uranium radionuclides at the plant. 

NIOSH lacks sufficient information, which includes sufficient non-uranium source term and chemical 

solubility information, that would allow it to estimate the potential total internal exposures to which 

the proposed class may have been exposed. 

8.0 Evaluation of Health Endangerment for Petition SEC-00067 

The health endangerment determination for the class of employees covered by this evaluation report is 

governed by EEOICPA and 42 C.F.R. § 83.14(c) and § 83.13(c)(3). Pursuant to these requirements, if 

it is not feasible to estimate with sufficient accuracy radiation doses for members of the class, NIOSH 

must determine that there is a reasonable likelihood that such radiation doses may have endangered 

the health of members of the class. The regulations require NIOSH to assume that any duration of 

unprotected exposure may have endangered the health of members of a class when it has been 

established that the class may have been exposed to radiation during a discrete incident likely to have 

involved levels of exposure similarly high to those occurring during nuclear criticality incidents. If 

the occurrence of such an exceptionally high-level exposure has not been established, then NIOSH is 

required to specify that health was endangered for those workers who were employed for a number of 

work days aggregating at least 250 work days within the parameters established for the class or in 

combination with work days within the parameters established for one or more other classes of 

employees in the SEC. 
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NIOSH has determined that members of the class were not exposed to radiation during a discrete 

incident likely to have involved levels of exposure similarly high to those occurring during nuclear 

criticality incidents. However, the evidence reviewed in this evaluation indicates that some workers in 

the class may have accumulated chronic radiation exposures through unmonitored intakes of 

non-uranium radionuclides. Consequently, NIOSH is specifying that health may have been 

endangered for those workers covered by this evaluation who were employed for a number of work 

days aggregating at least 250 work days within the parameters established for this class or in 

combination with work days within the parameters established for one or more other classes of 

employees in the SEC. 

9.0 NIOSH-Proposed Class for Petition SEC-00067 

The evaluation defines a single class of employees for which NIOSH cannot estimate radiation doses 

with sufficient accuracy. This class includes all AWE employees who were monitored, or should 

have been monitored, for exposure to ionizing radiation while working at the Allied Chemical 

Corporation Plant in Metropolis, Illinois, for a number of work days aggregating at least 250 work 

days from January 1, 1959 through December 31, 1976 or in combination with work days within the 

parameters established for one or more other classes of employees in the SEC. 
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10.0 References 

42 C.F.R. pt. 81, Guidelines for Determining the Probability of Causation Under the Energy 

Employees Occupational Illness Compensation Program Act of 2000; Final Rule, Federal 

Register/Vol. 67, No. 85/Thursday, p 22296; May 2, 2002; SRDB Ref ID: 19391 

42 C.F.R. pt. 82, Methods for Radiation Dose Reconstruction Under the Energy Employees 

Occupational Illness Compensation Program Act of 2000; Final Rule; May 2, 2002; SRDB Ref ID: 

19392 

42 C.F.R. pt. 83, Procedures for Designating Classes of Employees as Members of the Special 

Exposure Cohort Under the Energy Employees Occupational Illness Compensation Program Act of 

2000; Final Rule; May 28, 2004; SRDB Ref ID: 22001 

42 U.S.C. §§ 7384-7385 [EEOICPA], Energy Employees Occupational Illness Compensation 

Program Act of 2000; as amended; available on OCAS website 

OCAS-IG-001, Internal Dose Reconstruction Implementation Guide, NIOSH, Office of 

Compensation Analysis and Support (OCAS); Rev. 1; August, 2002; 

http://www.cdc.gov/niosh/ocas/ocasdose.html 

OCAS-IG-002, External Dose Reconstruction Implementation Guide, NIOSH, Office of 

Compensation Analysis and Support (OCAS); Rev. 0; August, 2002; 

http://www.cdc.gov/niosh/ocas/ocasdose.html 

ORAUT-OTIB-0006, Technical Information Bulletin: Dose Reconstruction from Occupationally 

Related Diagnostic X-Ray Procedures; Rev. 3 PC-1; December 21, 2005 

ORAUT-OTIB-0024, Estimation of Neutron Dose Rates from Alpha-Neutron Reactions in Uranium 

and Thorium Compounds; Rev. 00; April 7, 2005 

ORAUT-TKBS-0044, Site Profile for Allied Chemical Corporation Plant, Rev. 00, ORAU Team 

Dose Reconstruction Project for NIOSH; February 1, 2006 

Bioassay, 1986, Policy and Procedure for Bioassay Sampling, Allied Chemical; 1986; SRDB Ref ID: 

12376 

Honeywell, 1996, Procedure for Bioassay Sampling; Honeywell, 1996, page 80 of .pdf file; SRDB 

Ref ID: 12378 

Landauer, 1970, Landauer Dosimetry Information from the 1970’s, copy of the key to a 1970s-era 

dosimetry report faxed to Milton Gordon (ATL) from Barbara Koperski (Landauer); October 27, 

2004; SRDB Ref ID: 23570 
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Perkins, 1982, Evaluation of Environmental Control Technologies for Commercial Nuclear Fuel 

Conversion (UF6) Facilities, Perkins, B. L.; Los Alamos National Laboratory; October, 1982; SRDB 

Ref ID: 12379 

Site Procedures, 1985, Assorted monitoring results, meeting minutes, and misc. site information; 

Allied Chemical, Metropolis Works; various dates; SRDB Ref ID: 12374